Coupling submersible to service craft

ABSTRACT

A submersible unit is coupled to a service craft under water while being stabilized and centred by means of arms carrying pontoons, which are raised to engage the service craft.

United Staies Patent [191 [111 3,724,410

Lok [451 Apr. 3, 1973 [54] COUPLING SUBMERSIBLE TO [56] References Cited SERVICE CRAFT UNITED STATES PATENTS [75] Inventor: Harmannus Henderikus Lok, ler- 3 H9 127 H1964 T ,rt 9/1 T agge Seke Netherlands 3,448,712 6/1969 Lehmann et al.... ..1 14143.5

[73] Assignee: Nereid N.V., Ierseke, Netherlands 3,596,623 8/1971 Frankel ..l14/43.5

[22] Filed: 1971 Primary Examiner-Trygv'e M. Blix [21] Appl. No.: 137,523 Attorney-Diner, Brown, Ramik & Holt [52] US. Cl. ...ll4/16 R, 114/435 [57] ABSTRACT [51] Int. .Cl. ..B63g 8/00, B63b 35/44 A s bm rsible unit is coupled to a service craft under [58] Field of Search ..1 14/5 R, 43.5, 16 R; 9/1 T water while being stabilized and centred by means of arms carrying ontoons, which are raised to engage the service craft.

10 Claims, 4 Drawing Figures PATENTEDAPRB 197s SHEET 1 BF 2 INVENTOR. HARMANNU) Hcuusmxus LoK BY PATENTEDAPRB I975 3,724,410

SHEET 2 BF 2 INVENTOR HARMANNUS HENDERIKUS LoK COUPLING SUBMERSIBLE T SERVICE CRAFT This invention relates to a method of carrying out'a coupling maneuver between two vessels, at least one of which comprises at least one pontoon connected to a hull. The invention also relates to a vessel equipped for the performance of said method.

Such a method is of importance, for example, in exploration work by means of submersible units. Such units, which may or may not be self-propelling, accommodate personnel in a cabin, the unit being maneuvera-' ble for floating on the surface or for diving by suitable manipulation of the pontoon and ballast provisions.

In various operations, such a submersible unit cooperates with service craft, such as a mother ship, a platform, and/or another submersible craft. Even in moderately rough seas, the connection between the diving unit and the service craft constitutes a problem. If a flexible connection is used, there must be adequate spacing between the two vessel. If a more or less rigid connection is used, difflculties are encountered in coupling and uncoupling operations.

It is an object of the present invention to provide an improved method in this respect, so that two vessels may be coupled in a simple and reliable manner even in rough seas.

The invention also has for its object to provide a vessel equipped for easy achievement of coupling procedures, using the method according to the invention.

According to the invention, there is provided a method of carrying out a coupling maneuver between two vessels at or adjacent the water surface, in particular in waves, such as at sea, at least one vessel comprising at least one pontoon connected to a hull, characterized in that the hull of said at least one vessel is stabilized by controlling a positive buoyancy by means of said of least one pontoon, so that at least a portion of the pontoon projects above the water, and a coupling member of said one vessel is brought into a correct coupling position by the vertical displacement of the pontoon relative to the hull, which coupling member is then connected to a corresponding member of the other vessel.

The invention further provides a vessel comprising a hull with a coupling member for coupling with another vessel and at least one pontoon connected with the hull, the vessel being equipped to be coupled with another vessel by the method according to the invention in that said at least one pontoon is connected to the hull for movement in a vertical direction in the floating condition of the vessel, there being provided means for positive displacement of the pontoon relative to the hull in at least one direction.

By virtue of the invention, the draught of the one vessel can be easily controlled, so that, for example, its rolling characteristics can be better controlled and adapted to those of the other vessel, while a rigid coupling with a submerged member of the other vessel can be readily achieved.

A vessel according to the invention preferably has a plurality of pontoons arranged symmetrically relatively to a vertical plane containing the horizontal axis of the hull, and secured to carrying arms pivoted on shafts extending parallel to the horizontal axis of the hull. With this construction there may be sufficient space between the pontoons in their raised position, into which another vessel can navigate vertically above the submerged hull, and whereby easy coupling between that vessel and the hull can be achieved. In this situation, that is, in which one vessel is vertically above the other, they will be subject to the same movements in rough seas, whereby the risk of collisions is minimized. This can be improved to an even greater extent by using the v buoyancy of the pontoons for them to assume their highest position relative to the hull, and making the means for the displacement of the pontoons relative to the hull yieldable in one direction, so that the carrying arms mounting the pontoons, possibly'provided with buffers, can be yieldingly urged against the other vessel during the coupling operation.

This construction is also extremely suitable for use with a coupling platform permanently located near the surface, which can then easily dock a surfaced submersible vessel, a habitat, and like units. Owing to the fact that the pontoons are partly above the water, the submerged hull will assume a stable position. Since prior to the coupling operation parts of both the platform and the surfaced unit extend above the water level, the craft can locate one another properly by means of light or radio beacons mounted thereon.

One embodiment of the invention will be described, by way of example, with reference to the accompanying drawings. In said drawings,

FIG. 1 shows a submersible unit according to the invention in side elevational view;

FIG. 2 shows the unit of FIG. 1 in front elevational view;

FIG. 3 shows the unit coupled to another vessel in side-elevational view; and

FIG. 4 illustrates a front view of the showing of FIG. 3.

Referring to the drawings, a first vessel generally designated by l, in this example a submersible unit, comprises a cabin 2 into which crew can enter through a lock 3, and which accommodates controls. Disposed under, and connected to, cabin 2 is a platform 4 carrying ballast or freight 5. Mounted on opposite sides of the cabin are arms 6 with pontoons 7. These arms are pivoted on hinges 8, and can be driven from a drive 9. Berths 10 for coupling with another vessel are provided on the top of cabin 2. Numeral 11 designates the seabed in FIG. 1 and 2. In FIG. 2, the water level is designated by 12 to show the level to which the unit will be submerged in floating condition, in which condition it is not, of course, resting on the seabed.

FIG. 3 and 4 show the unit 1 coupled to a kind of mother vessel 13. In the example shown, the mother vessel is a self-propelled submersible work craft with a crew cabin 14, thrust l5 and auxiliary propulsion l6 and feet 17. Such a craft is described in my co-pending application Ser. No. 51420, filed July I, 1970. The feet 17 can be accommodated in the berths 10 of the submersible and be fixed by means of couplings 18.

In the free-floating condition of unit 1, in which the water level will be at 12 in FIG. 2, the lock 3 projects above the water. In order to couple the unit to the mother vessel, lock 3 is closed and arms 6 with pontoons 7 are released. Owing to the relative buoyancy of the pontoons, the arms 6 will pivot upwards to approximately the position shown in FIG. 4. Drive 9 is constituted by a set of multi-sheave blocks movable apart by means of an hydraulic jack. The jack is of the singleacting kind, the working fluid, such as air or liquid, being supplied from a supply tank by means of an electric pump or a hand pump. Naturally the movement of the arms can be effected by other means, for example by means of connecting rod assemblies and the like. The advantage of a rope construction is that a rope can only take tensile forces, so that in the case of bumps or collisions between the mother vessel 13 and arms 6 in the position of FIG. 4, the arms can yield. The arms may additionally be provided with resilient buffers 19 for the purpose.

As arms 6 pivot upwards, cabin 2 will gradually be lowered under the water level 12, the pontoons 7 carried at the ends of the arms emerging from the water as shown in FIG. 4. The mother vessel 13 can then be maneuvered between arms 6, and can thus be maintained in a quiescent state relative to the unit by the resilient bias from arms 6, so that the coupling operation can proceed in an extremely simple manner. When pontoons 17 have come to rest on berths 10, to be realized by increasing the buoyancy of the submersible unit or decreasing the buoyancy of the service vessel, or by decreasing the draught of the first vessel, the unit and the mother vessel can be coupled together by means of couplings 18. It will be clear that it would also be possible to effect a coupling between the lock of the submersible unit and corresponding facilities of the mother vessel.

When the coupling operation has been completed, the buoyancy of the assembly can be reduced, whereafter the mother vessel can transport the unit to a desired site, for example, on the sea bed, if the latter has no propulsion of its own, or one with insufficient power.

After the removal of the buoyancy the submersible unit will come to rest on the seabed at the desired site. When the motor vessel has been uncoupled she can withdraw, whereafter the unit is anchored in a stable position by pivoting arm 6 downwards. If desired, arms 6 are provided with flukes 20 for fastening in the ground. 4

The diving unit can the be used, for example, as a shelter for divers operating at deep-sea level. Such shelters or habitats are used in order that divers need not continually come to the surface, which would require their staying in a decompression tank for prolonged periods of time, which would be a waste of useful working hours.

Besides coupling the diving unit to a submersible craft, the unit may be directly coupled to a surface mother vessel, while naturally a similar coupling procedure would be possible between the mother vessel 13 described in this example, with a submarine mother vessel, if vessel 13 is provided with vertically movable pontoons.

Although, inthe above example, the first vessel is a submersible unit, it should be noted that, for the purposes of this invention, the first vessel may as well be a coupling platform. In that case there is no cabin 2, or cabin 2 constitutes part of platform 4. the carrying arms 6 and propulsion 9 being directly mounted on the platform. Such a coupling platform can then remain near the water surface for berthing submersibles surfaced from the seabed, and for their further handling,

for example, transport to a port.

I claim:

1. A submersible vessel comprising a buoyant h'ull, a support depending from said hull for supporting said hull on a bed of a body of water, an arm pivotally attached to said hull on each side v thereof for pivotal movement relative to and generally alongside said hull, each of said arms including bouyant means, said arms being normally urged by said bouyant means to a generally upstanding position extending above said hull and thus lowering the center of buoyancy of said vessel and causing said hull to be submerged, and drive means for moving said arms to and retaining said arms in a position extending downwardly and laterally away from said hull with ends of said arms remote from said hull being generally coplanar with a lower part of said support and laterally spaced therefrom for engagement with the same body of water bed as said support to stabilize said vessel in a submerged position resting on a bed ofa body of water.

2. The submersible vessel of claim 1 wherein said arm ends remote from said hull include anchor means for engagement in the bed of a body ofwater.

3. The vessel of claim 1 wherein said hull is in the form of a cabin for a crew.

4. The vessel of claim 1 wherein said bouyant means are in the form of plural pontoons carried by each arm spaced along the respective arm and disposed generally remote from said hull.

5. The vessel of claim 1 wherein each arm is connected to said hull by a pivot and each pivot is located above said hull.

6. The vessel of claim 1 together with means above said hull for clamping engagement with an overlying mother vessel for transportation by the mother vessel.

7. The vessel of claim 1 wherein said drive means include a multi-sheave block assembly, one block being pivotally connected to said hull, a line entrained over said blocks and having an end portion secured to a respective arm, and an extensible jack mounted between the two blocks for urging said blocks apart.

8. A method of connecting together two floating vessels at sea while the vessels are subject to wave action, said method comprising the steps of providing said vessels with cooperating coupling means, providing a first of said vessels with floatation means and drive means for varying the vertical position of said floatation means, floating said first vessel in a submerged state with portions of said floatation means disposed above the water surface, floating the second of said vessels generally on the water surface, guiding said second vessel into vertical alignment with said first vessel utilizing said floatation means as guides, modifying the buoyancy of one of said vessels to bring said vessels vertically together, and positively securing said vessels together by engaging said coupling means.

9. The method of claim 8 together with the added step of reducing the buoyancy of the coupled together vessels and moving said vessels as a unit.

10. The method of claim 9 wherein said first vessel is released from said second vessel and caused to rest on an underlying seabed, and said flotation means are lowered to engage the seabed in laterally spaced rela- 

1. A submersible vessel comprising a buoyant hull, a support depending from said hull for supporting said hull on a bed of a body of water, an arm pivotally attached to said hull on each side thereof for pivotal movement relative to and generally alongside said hull, each of said arms including bouyant means, said arms being normally urged by said bouyant means to a generally upstanding position extending above said hull and thus lowering the center of buoyancy of said vessel and causing said hull to be submerged, and drive means for moving said arms to and retaining said arms in a position extending downwardly and laterally away from said hull with ends of said arms remote from said hull being generally coplanar with a lower part of said support and laterally spaced therefrom for engagement with the same body of water bed as said support to stabilize said vessel in a submerged position resting on a bed of a body of water.
 2. The submersible vessel of claim 1 wherein said arm ends remote from said hull include anchor means for engagement in the bed of a body of water.
 3. The vessel of claim 1 wherein said hull is in the form of a cabin for a crew.
 4. The vessel of claim 1 wherein said bouyant means are in the form of plural pontoons carried by each arm spaced along the respective arm and disposed generally remote from said hull.
 5. The vessel of claim 1 wHerein each arm is connected to said hull by a pivot and each pivot is located above said hull.
 6. The vessel of claim 1 together with means above said hull for clamping engagement with an overlying mother vessel for transportation by the mother vessel.
 7. The vessel of claim 1 wherein said drive means include a multi-sheave block assembly, one block being pivotally connected to said hull, a line entrained over said blocks and having an end portion secured to a respective arm, and an extensible jack mounted between the two blocks for urging said blocks apart.
 8. A method of connecting together two floating vessels at sea while the vessels are subject to wave action, said method comprising the steps of providing said vessels with cooperating coupling means, providing a first of said vessels with floatation means and drive means for varying the vertical position of said floatation means, floating said first vessel in a submerged state with portions of said floatation means disposed above the water surface, floating the second of said vessels generally on the water surface, guiding said second vessel into vertical alignment with said first vessel utilizing said floatation means as guides, modifying the buoyancy of one of said vessels to bring said vessels vertically together, and positively securing said vessels together by engaging said coupling means.
 9. The method of claim 8 together with the added step of reducing the buoyancy of the coupled together vessels and moving said vessels as a unit.
 10. The method of claim 9 wherein said first vessel is released from said second vessel and caused to rest on an underlying seabed, and said flotation means are lowered to engage the seabed in laterally spaced relation to stabilize said first vessel. 